Stay-bolt for boilers.



B. E. D. STAFFORD 6I E. I. DODDS.

AY BoLTFon BoILEnS.

B. E, D. STAFFORD L 5.! DODDS STAY BOLT FR BLEHS l APPLICATIAN HLD NOV-24 15H41 1,236,015. l;muf\dAu 7 1917 2 SHEETS SHEET V Gunnar we gn-,afaarar nom co "To all whom it may concern;

' STAFFORD and E'rnniv V and useful Improvements [Be itkn'own that we, BENJAMIN E. D. Donns, citizens of the United States, and residents ci Pittsof. ennsylvania, have invented certain new Boilers; and we do hereby declare the following to be a. full, clear, -and exact descrip in,- sta bolts for boilers, the object being tol provi e a yieldingcoupling for one end of the bolt, whereby the latter' will be liexibly supported so that itmay be` free tol follow the movements of the fire boxsheet ofl the boiler without unduly straining either of the sheets. v

With this object in view our invention consists in a sleeve composed of twofdetaehwithout unduly straining boiler, and

rounded seat' or the head 3 'of the stay bolt ther end to vthe inner abl connected members the outer one-of Wluch `is, Constructed to yield ,or give and thus permit the stay bolt, the head of which is in` contact with self to the movements ofthe boiler sheets sheets.

I n the accompanying drawings, Figure 1 is ai view in elevation of a coupling sleeve embodying our invention; Fig. 2 is a view in section through same andalso `showing the bolt in -place and Figs. 3, 4, 5, V5', 6,17, 8, 9, 10, 11 and `12 are views in section of modified forms.

1 represents s. bushing threaded externally for its attachmenttothe outer sheet of -a rovided internally with a 4, the. latter ,adapted tobeseeured at its sheet of the'- boiler. The bushing 1 is made flaring from the seat 2 to its `inner end, so as trpermit the bolt 'w have the necessary rocking movement on its seat in the bushing. Secured to the outer threaded of spring ymetel or'stay be -metal heat treated and cooled in oil so as'to render `it yielding. This' cap is rovided wtli'one 'or Specification of Letten Patent.

burgh, in the county of Allegheny and State im Stay-Bolts foi" as will enable same, to accommodate i'teither of the longitudinal e endof the bushing 1 is the'cap whichis, Areferably milde rbushin and agaliillfthe head convolutions,

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, frof Application med November 24, 1914. Serial No. 7892 longitudinal ressure orfstx. r

the bolt. t e construction" .1 and 2 the central portion ofthe grojected inwardly'in the form of a t .Y the free end which is curved concentric with the curved bearing 2, in buf y1, and rests against a concave seat 8 forme in the bolt head 3. The curved seat 8 is also concentric 'with the.cnrved seat 2, so that when the arts are assembled, the heed of the bolt is re'e to turn in un direction on its seat 2. The nipple 'I yiel 'ngly holds the iii b olt 4 onto its seat 2, butlthe spring forma- Y tion of the 'cap permits the nipple 7 to be f moved outwardly under ang longitudinal stresses that may be im arte to the bolt 4, thus permitting the bo t to respond to the movement of the fire box sheet of the boiler without :unduly straining either of the sheets. 'Wehave alsov shown the nippley 7 with a central bore 9, which communicates with the tell-tale 10 formed in the bolt,` so that in the event the bolt should be fractured at the juncture of the neck and head, which is the point where fracture nearly univer? sally occurs, 4the eteam or water .may 'issue through the'bore 9 and indicate the existence of a ructure in the bolt. l In Fi 3 we` have shown the ce V5 with a pluralityof folds 6*, the'centr partici the ca beingturned inwardly aset 11 -fto rform t e nipple, and flared downwardl so as to rest on the convex, seat 12 form on the outer end of the bolt, the convex seat 12 concentric with the sect2 so as tir-pel.`- mit t e bolt head 3* to turn freely on its seat.

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The construction shown in-.F1g. 4 issubstentially identical with that shown -in` fsof 3, except that the bolt head''J has a. concave' seat to lreceive the-"inwardly turned ,central nlpple 13er the cap 5", the curvature of the concentric withf seat Vin the bolt head bein the seat 2 for'the' bolt heel in the bushing 1.

Inthe construction shown' in Figs. 5 "and 5, the cap .5 is composed of twol members 5d and 5*, united around-the central eulefogfvv the` cap',`;th`e `free edgefofpthewiinner member. i `termin ating adjacentthejfdiiter end joil the Fig- 5; @relisted/'mahnt fee M- e of the inner memhermaybeac In Fig. 6 the cap 5t is'formed of aser'ies of folds within the outer member, the several folds vbeing substantially parallel and terminatingcentrally in an inwardly projecting hollow nipplef", the free end of which is roundedandv rests on a concave seat f,- at the bottom 0f. 1thereesswthn the head, the curvature'of the seatfa. and the rounded end 'f" lof Athe nipple f", being concentric with the curved. seat2y inthe socket 1..

In the construction shown in `Figuf?, the

folds extend .crcumferentially around the cap sub stantiallvy in [planes at rightangles to. thelong axis of .thefb'oli'q-l and the cap` is provided vcentrally,with` a hollow rnipple integral with the top fold, and terminating in` a curved head'g1 whichrests Within a con' cave seat g2 at thelcenter of thehead of the bo1t,.the said head g1 and seat g2 being com centric with the seat2 in bushing 1. The

construction disclosed in Fig. f8is fsubstan{ a" 'central bore which is internally threaded i the cap 51 vare diagonally disposed tothe except that the nipple gs* is sepanate, .oml the cap and is .secured-.thereto threads. Y v

In Fig. 9 the cap 5h is. .provided with folds formed in the cap substanti ally' atl.' right angles to the long axis of the b olt, one end.

of said folds h1 forming a seat forthehead of the bolt, the beating. face 'of :the 4fold being curved to conform to the curvature ofthe head. The ou+erendof the-,cap has and closed by vaplug h2, which may have a Atell-tale bore h3, for the escape, of steam.

or water@ v In Fig. 10 the foldspr. convollifcions in long axis of the bolt, -and thelatter is provided centrally with a threaded openingior the; nipple i, the lower endofE-whichis rounded and rests. on a concave. Seat-v vitlijn' a' recess rin theheadA ofzthetbolt aspreviously: described. The construction shown in Fig..

thefhead of thebolt.l

sleeve or bushinglk vprojectsv considerably' above 'the seat 2 onthehe'ad ,lihelqolifq and is internally/threaded .at its outer end tofreceive the cap 5m. The outer. endof this cap is made heavy and threaded externally, Tand the lower or inner part is hollow and convoluted or luted orfolded'so that it may give or yield under longitudinal stresses to turns it to its seat Withingthe bushing as soon as the longitudinal stress is relieved, and when so supporting the bolt, forms a steamn tight *jointwithi .the` head lof rthe. latter so as to prevent-theescape of steam or water. The bolt therefore .is .free to lhave a universal rocking movement in the bush ing, and is alsofree to move longitudinally, so that lvit can., respond themovements of the firel box sheet, without buckling4 or. -unduly straining either vof `the sheets.

Itis evident ,that many slightchanges might be. resorted to in the-.relative ari-rangement of partsl shown and described without departing from the spiritand scope of our invention. Hence we would have it =understood that we do not wish to confine ourselves to the exact construction andarrangement of lpaints shown and. described, except as `reqired by thescope: ofthe appended Having; fully described our invention what we elainia's' -new-iandl-.desireto secure by LetterssPatent ,is:-.

comprising a bolt having :van y'opening' formed therein, a sleevehavingfan opening `.throughy which said boltjpasses, a cap onfsaid-fsleeve,

said ca .beingprovidedwith van,opening,

llet arranged-fbetweengsaid-ca and largement formedvon saidibolt ,for-fen .agement with 'the recess fofzthe sleevefsai- 1 bolt .being provided .Witha bora-a recess-formed 1n said bolt .commilnicating with isaid-y bore betweeny said cap... and.. said- ..bolQ- ithei et beingqprovidedfwlth a ourvedaend for `eneing provided.v with fan., 1op`,e x 1il;1g,4 rinda an opening formed insaid fillet in 6 0 fedtionwiththe o ening in the-bolt .and cap.

3. .A stay-bo t comprising't a body' having an opening formed-therein and an enlarged end', a sleeve engagedaround-saidstay bolt and having a recess for Vaccomin'odating said ion enlargedend, a cap on' said sleeve, and a,V I'130 enlarged end of the said bolt, sai fillet serving to space said cap from said staybolt.

4. In stay bolts for boilers, the combina tion of a bushingadapted for attachment to the outer sheet of a boiler, a stay bolt the head of which is seated in said bushing, and a yielding or resilient Cap detaohably secured to said bushing and bearing against',

the head of the bolt.

5. In stay bolts for boilers, the combination of a bushing adapted for attachment to the outer sheet of a boiler and provided internally with a curved seat, a stay bolt hav'- ing a curved head resting on said curved. seat, and a yielding or res1lient cap detach ably secured to said bushing and forming a yielding abutment for the bolt.

6. A bushing for boiler stay bolts havin an internal seat for the head of thevbolt, an

yielding cap detaohably secured to said bushing and forming a yielding abutment against which the head of the 4stay bolt bears. 4

T. ln stay bolts for boilers, the combina-` tion ol a bushing having an internal seat for lthe head. of a stay bolt, a stay bolt having a head adapted to rest on said seat, and ay cap seemed to the bushing and having a bearing .for the head `of the bolt, the portion of the cap intermediate its attachment to the bush ing and its part which bears on the head of the bolt being yielding so as to permit it to give under endwise pressure on the bolt.

8. In stay `bolts for boilers, the combination of a bushing having an internal seat for the head of a stay bolt, a stay bolt having a head adapted to rest on said seat, and a cap secured to the bushing and havin a bearing against which the head of the bo t rests, the Asaid eap being uted or convoluted between its attachment to the bushing and its bear ing for the head of the bolt, whereby it is free to yield or give under endwise pressure o'the bolt.

9. ln stay bolts for boilers, the combination of a bushing having an internal seat for -the head of a bolt, a bolt having a head rest ing on said "swt, and a cap secured to the bushing and having an inwardly projecting end bearing against the head of the bolt an t forming an abutment for thesame, the portion of the cap intermediate its attachment to the bushing and its abutment for the bolt head being lu'ted or convoluted whereby it will be free to yield orgive under endwise pressure on the bolt.r i

10. In Stay bolts for boilers, the combination of a bushin having an internalseat for the head of a bo t, a bolt having a head resting on said seat the said bolt head having a tell-tale bore and a cap secured to the bushing and bearing against the head, the Said cap having an opening in alinement with the tell-tale bore in the bolt head and also shaped intermediate said opening and secured end so that it can give or yield under longitudinal stresses imparted to the bolt.

1l. In stay bolts for boilers, the combina tion of a stay bolt, a seat for the head ofthe saine and a yielding resilient eap'secured to the alt having the seat and bearing againste the l, ieadpf the bolt.

In testimony whereof, we 'have signed this speeilieation in the presence of two subscribing witnesses. y

BENJAMIN E. D. STAFFORD. v ETHAN I. DODDS. A

Witnesses:

EDWIN S. RYGE, Howarth O. Carrier.. 

